This invention is a system and apparatus for installing a central tire inflation (CTI) valve in a wheel hub bore.
FIG. 1 provides an example of a one-piece wheel assembly 1 with a hose fitting 2 mounted to the vehicle hub (not shown) in accordance with the teachings of prior art. The one-piece wheel assembly 1 includes a wheel 3 with tire 4. Parts of wheel 3 include rim portion 5, transverse wall or “disc” portion 6, drop center area 7, an air duct formed by airway 8, and a central opening, hub bore area 9. Hose fitting 2 connects to an air hose 10; the air hose 10 connects to the wheel 3 via another hose fitting 11. The tire 4 and rim 5 form a tire chamber 12 that contains a pressurized fluid (usually air).
Similarly, FIG. 2 shows a section of a two-piece wheel assembly 13 configured for an externally mounted CTI valve 15 and a quick release valve 14 mounted on a two-piece wheel 16 in accordance with prior art. The two-piece wheel assembly 13 includes the two-piece wheel 16 and tire 4. Parts of wheel 16 include rim portion 5, disc portion 6, rim flat area 17, and a central opening (hub bore area 9). The tire 4 and rim 5 form a tire air chamber 12 that contains a pressurized fluid (usually air). Two-piece wheels 16 are usually used when a bead lock 18 or run flat device (not shown) are utilized in the two-piece wheel assembly 13. Two-piece wheels 16 consist of two major parts, the inner rim half 19 and outer rim half 20. The two rim halves 19 and 20 are sealed with an o-ring 21 to prevent air from escaping out of tire air chamber 12. Bolts 22 and nuts 23 hold the two rim halves 19 and 20 together.
Finally, FIG. 3 shows a section of another two-piece wheel assembly 24 configured for an integrated CTI valve 25 attached to the wheel. The configuration shown is the same as in FIG. 2, except the CTI valve 25 uses an airway 26 from the vehicle hub (not shown) to the CTI valve 25 and an air duct formed by airway 27 from the CTI valve 25 to the tire cavity 12. (The CTI arrangement and internal passageways 26 and 27 are patented under U.S. Pat. No. 6,474,383 and European Patent EP 1 262 340 A2).
As the preceding figures illustrate, current CTI valve technology may employ any one of several air passageway configurations. Thus, as illustrated in FIG. 1, a hose fitting 2 mounted on the vehicle hub (not shown) can bring air through a hose 10 to a hose fitting on the wheel 11. Alternatively, as illustrated in FIG. 2, a hose fitting 28 on the vehicle hub (not shown) can bring air through a CTI air hose 29 to a quick release valve 14 mounted on the wheel 16. Another CTI air hose 30 channels air from the quick release valve 14 to the external CTI valve 15, while CTI air hose 31 brings air from the external CTI valve 15 to a sealed hose fitting 32 on the wheel 16. Finally, as illustrated in FIG. 3, an integrated CTI valve 25 can be mounted on the wheel 16. An airway 26 in the wheel brings air from a port on the vehicle hub (not shown) to the integrated CTI valve 25. A second airway 27 in the wheel brings air from the integrated CTI valve 25 to the tire cavity 12. (Cf., U.S. Pat. No. 6,474,383 and European Patent EP 1 262 340 A2). In all of these examples, the systems described allow the tire cavity 12 to be inflated or deflated via a control system in the vehicle as necessary to facilitate and optimize vehicle operation and performance.
However, all of the aforesaid methods and apparatus have disadvantages. These disadvantages include the fact that: (a) rocks, curbs, or brush can damage externally mounted valve configurations with hoses during vehicle operations; (b) rocks, curbs, or brush can damage integrated CTI valves mounted on the face of the wheel during vehicle operations; (c) both externally mounted and integrated CTI valves are “bulky” and take up a lot of space on the wheel face; (d) both externally mounted and integrated CTI vales require the airway in the wheel to be aligned with the airway in the vehicle hub; (e) externally mounted CTI valves with hoses and fittings typically contain a high number of components; (f) externally mounted CTI valves with hoses and fittings are complex and difficult to assemble; (g) externally mounted CTI valves and hoses result in excessive weight and increased wheel imbalance; (h) externally mounted CTI valves are highly visible and are more susceptible to damage from hostile fire (on military wheels) or sabotage by cutting the external tubing; (i) externally mounted CTI valves contain a higher number of components resulting in an increased number of leakage points; (j) externally mounted CTI valves contain a higher number of components results in increased cost; (k) externally mounted CTI valves contain a higher number of components resulting in increased time required to assemble and disassemble; (l) hose fittings can be easily stripped or damaged during assembly/disassembly; (m) integrated CTI valves mounted towards the rim portion of the wheel result in significant wheel imbalance and increased weight due to the counter balance weight required; and (n) as illustrated in FIG. 4, some CTI valves require heavy covers 33 for protection, further exacerbating several of the problems previously described.